FastAPI Utilities

0.3.1 verified Mon Apr 27 auth: no python

A collection of reusable utilities for FastAPI including repeat, repeat_every, on_startup, and task decorators. Version 0.3.1 (requires Python >=3.7, <4.0). Release cadence is irregular.

pip install fastapi-utilities

Common errors

error AttributeError: module 'fastapi_utilities' has no attribute 'repeat_every' ↓

cause Old import path used, or package not installed correctly.

fix

Run pip install --upgrade fastapi-utilities and use from fastapi_utilities import repeat_every.

error ImportError: cannot import name 'repeat_on_startup' from 'fastapi_utilities' ↓

cause Incorrect function name (does not exist).

fix

Use from fastapi_utilities import on_startup.

error TypeError: 'NoneType' object is not callable ↓

cause Decorator order reversed: `@repeat_every` placed above `@app.on_event`.

fix

Ensure @app.on_event('startup') is the outermost decorator.

Warnings

gotcha The decorator order matters when combining @app.on_event('startup') with @repeat_every: @app.on_event must be the outermost decorator. ↓

fix Apply @app.on_event on top, then @repeat_every.

deprecated The `repeat` decorator (without _every) is deprecated and may be removed in future versions. ↓

fix Use `repeat_every` or `repeat_at` instead.

gotcha Task functions must be async; the decorator does not support synchronous functions. ↓

fix Define the task with `async def`.

breaking In version 0.2.0, the package name was changed from `fastapi-utils` to `fastapi-utilities`. Install with the new name. ↓

fix Use `pip install fastapi-utilities`.

Imports

repeat_every

wrong

from fastapi_utilities.repeat import repeat_every

correct

from fastapi_utilities import repeat_every

repeat_every is exposed at package level; do not use submodule path.

repeat_at
```
from fastapi_utilities import repeat_at
```
Added in 0.2.0.
on_startup
```
from fastapi_utilities import on_startup
```
Simple decorator; do not use app.add_event_handler with this.

Quickstart

Minimal example: on_startup and repeat_every decorator.

from fastapi import FastAPI
from fastapi_utilities import repeat_every, on_startup

app = FastAPI()

@on_startup
async def startup():
    print("App started")

@app.on_event("startup")
@repeat_every(seconds=30)
async def periodic_task():
    print("Task executed")